Condenser



Feb. 21, 1933. P.. B. BENJAMIN 1,898,808

CONDENSER Feb. 2l, 1933.

3. B. BENJAMIN coNDENsFR` 3 Sheets-Sheet 3 File@ Dec.

i Patented' Feb. 21, 1933 l sired relation b --UN1TED sTATEsrA'rENr .OFFICE BEUBEN B. BENJAMIN, 0F CHICAGO, ILLINOIS, ASSIGNOB T0 BENJAMIN ELECTRIC MANUFACTURING COMPANY, 0F DES PLAINES, ILLINOIS, A CORPORATION Ol' ILLINOIS y i CONDENSER.

Application illed December 18, 1928. Serial No.'154,384.

My invention relates to condensers and partcularly to condensers of the concentric type, the plates of which are brought into the deaxial movement.

The object o my invention is to provlde a cheap, simple and eiiicient condenser of rugged construction while comparatively light in Weight and in which the movable 1 reference' characters refer to and indicate like plates are prevented from being moved out of their proper relation with the stationary plates.

Another object is to provide a condenser so constructed that the necessary parts together form a metallic dust-tight shield protecting the blades from accidental injury and formv ing an electric shield.

Another object of my invention is to provide a condenser in which the movable plates are of such form as to provide a straight line frequency eilect when the same are moved in relation to the stator plates.

A still further object of my invention is `to provide a multiple condenser having improved means for controlling the movement of the individual units.

Another obj ect is to provide means for adjusting the rotor with regard tothe stator independently of the central operating shaft so as to alter the capacity relation.

Other objects and advantages of my improved condenser will be apparent to those skilled in the art when considered in connection with the/following description, reference being had to the accompanying drawings, in which- Figure 1 is a longitudinal sectional view of a three-unit multiple condenser incorporating the principles of my invention;

Fig. 2 is a like view of a two-unit multiple condenser;

Fig. 3 is a cross-sectional view on the line 3-3 of Fig. l;

Fig. 4 is a single unit condenser of the sarie general type as that shown in Figs. 1 an 2;

Fig. 5 is an outer end'view of the condenser shown in Fig. 4;

Fig. 6 is a detail sectional view showing the mechanism employed on the slider units for positioning them with relation to the parts. 5

Referring to the drawings in detail and particularly to Fig. 1, wherein is shown a three-unit multiple type of condenser, said units being characterized by the letters a, b, and c, each consisting of a stator 11 and slider 12 cast from any suitable material, the stators are provided with a circumferential flange 13 havlng circumferential grooves 14 therein for receiving the cylindrical casing members 16 which position the said units the desired distance from each other.

The sliders of the units a and b are mounted on a hollow shaft 17 which extends through the stator of the units a and b and surrounds the solid inner shaft 18, which latter shaft extends through the panel 19 and is rovided at its inner end with an operating knob 21 securedy thereon by means of the set screw 22, while the outer end of said shaft is provided with a limiting collar 23 which is secured thereto by means of the pin 24. Beyond the said collar 23 are a air of lock nuts 26 while between the said limiting member and the outer face of the stator unit c is a spring'washer 27 which urges the shaft outward at all times so that the cylindrical plates or leaf portions 28 on the sliders 12 in each of the units may properly nest between the cylindrical plates 29 on the several stator units. The limiting collar 23 is provided with a finger 31 which is adapted to limit the rotary movement of the shaft 18 by striking against the pin 32 mounted on the outer face of the stator of the unit c so that when said shaft is operated by the knob 21 it is limited in its rotation to slightly less than 360. `The cylindrical plates or leaf portions 28 and 29 of the slider and stator respectivel are tapered throughout their len th and t e length of the plates is graduate from the inneri ings hard to remove. By tapering the fingers l have found that this objection is minimized and the castings are easily removable from the mold. The ends of the plates are rounded to conform to the shape of the metal between the inner ends of the plates. l

The slider 12 of the unit c is also mounted on a hollow shaft 33 which surrounds the solid inner shaft 18 and is secured to said inner shaft by the pin 34 so as to rotate therewith.

rlhe inner end of the device is provided with a base 36 whose outer face is of the same contour as the outer faces of the stator members 11 so that as it is approached by the slider 12 of the unit a the same capacity condition will be present as between the sliders 12 of the units b and c and the vouter faces of the stators a and b respectively. This base is also provided with a circumferential flange member 37 which has a circumferential groove 38 therein for receiving the inner end of one of the casing sections 16, while a bolt 39 extends through the flanges 13 on the stators 11 and into a tapped hole 41 in the flange 37 of said base so as to effectually connect all the said units together in the casing l sections 16. This base is secured to the panel 19 by means of flat-head screws 42 which eX- tend into bosses 43 on said base. The base is provided with a central opening 44 through the center of the sa-meand with a contiguous groove 46 in which the ring key 47 mounted in the annual groove 48 on the hollow shaft 17 is adapted to rest so as to limit the longitudinal movement of said shaft with respect thereto. A limiting collar 49 is mounted on the hollow shaft 17 and is adapted to rest against the inner face'of the base member and this limiting collar is secured to the hollow shaft by means of the pins 51 which extend through the said collar and hollow sha-ft only and said member has a finger 52 extending therefrom and adapted to strike against the shoulder 53 on the base 36 so as to limit the rotary movement of said hollow shaft to slightly less than 360. Immediately in front of the member 49 the hollow shaft 17 is provided with a threaded portion 45 for receiving the lock nuts 45 while between said members and said nuts a spiral spring 50 is adapted to rest for keeping said shaft under tension.

Mounted on the inner end of the hollow shaft is the rotary dial 54 which has a knob .portion 56 complementary to the knob 21 and this dial and knob portion 56, which are integrally formed, areI secured to the hollow shaft 17 and against rotation relative thereto by means of the set screw 57. rilhe inner face of the knob portion 56 is provided with an arcuate groove 58 which extends for a distance of 90, while a small integral tongue 59 on the outer face of the knob 21 is adapted to rest within said arcuate groove and said tongue limits the independent movement of said knob to the circumferential length of said groove. i

The hollow shaft 17 is provided with a spiral groove 61 which in the present design has a pitch of eleven-siXteenths of an inch but it is understood that l do not limit myself to this pitch as others may be found equally or more` advantageous for certain conditions. The hollow shaft 33 is also provided with a spiral groove 62. .lhe sliders 12 have a cen- 120o apart. Extending over the hole 68 on each of the sleeves and with the reduced portions 69 on its ends fitting within recesses in the plates 66 and 67 is a. guide-plate 71 which has a pressed-in port-ion 72 about the center of the opening 68 in said sleeve and the reduced inner end ofwhich is substantially the same shape as and engages in the circumferential groove 61 so that the said sliders 12 are governed in their movement by the turning of the shafts 17 and 3 3. These guide-plates 71 being secured in the insulating plates 66 and 67 and with the rivets 65 have no electrical connection with the sliders. The inner faces of the sliders 12 are each provided with apair of diametrically opposite lugs 73 and 74 and the lug 74 is used as a current-outlet member and has a hole 76 therein for the reception of a sprin'g'wire conductor end 84 of said spring conductor is soldered or otherwise fixed to said terminal member while a lead 85 is also secured to said member 83 and carried to any desirable point for A' properly wiring the apparatus.

The lugs 73 are drilled, as shown at 86 in Fig. 3, to receive the reduced end 87 of a v'guide-pin 88 which slides in the gui-de 89 formed by the two vertical ribs` 91 which are pressed in the guide plate 92. By employing a spring wire conductor the guide `pin 88 which slides in the guide 89 is always pressed or urged against one of the vertical ribs 91 so that there can be no capacity variation by the wobbling of the pin therein. This plate 92 is mounted on the casing section 16 by means of a rivet 93 passing loosely through the said casing and through a longitudinal slot 94 in one end of the same, while at a point intermediate the other end of said plate and the groove 89 is a set screw 96 which is securely fiXed in said plate and operates in a longitudinal slot 97 which is of substantially the same width as the body portion of said set screw so that upon .screwing the head thereof down tightly against the casing wall the plate is fixed against movement. At a point near the right-hand end of the plate 92 an eccentric member, shown in Fig. 8, is secured thereto by the tubular portion 100 being swaged or spread so that the eccentric portion 98 is revolvably fixed in said plate while the slotted member 99 rests within a vertical slot 101 cut in the casing section 16 so that when the said set screw 96 has been loosenedthe plate 92 may be moved circumferentially on the inner face of the casing section 16 by placing a screw driver within the slot 102 of the slotted member 99 and rotating the same, afterv which the set screw 96 is again screwed down tightly with its head against the casing 16 so as to secure the said plate in a fixed position. This is for securing minute adjustment of the condenser units by a slight rotation of the slider without the necessity of taking the apparatus apart or dismantling the same. These guide plates and adjusting mechanisms inthe units a, b, and c are placed 120 apart and are always diametrically opposite :to the lug 74 which carriesthe conductor of their' respective unit.

a solid shaft which is designated in saidl figures as 17 and 17erl respectively. The double knob 21 and 56 will also be eliminated and a Ysingle operating knob-.having a dial thereon, conforming to thev onedesignated as V56 in Fig. 1, willbe mounted directly on the end of. the shaft 17 and 17 a.

Both the statorand slider units are preferablydie cast and by reason of their each being a one-piece construction the resistance 'of each integral unit is very materiallyV reduced.4 This integral construction is of considerable importance as all losses due to poor contacts* between adjacent plates and the .shape of the dielectric plates and the varied length of the same, straight line frequency tuning can be readily accomplished and the matching of the condensers can also be readily effected by the eccentric adjustment device described.

This matching can be eected either in an intermediate lposition of the slider or when same is in full capacity relation with the stator. j

By reason of the constructionof the casing sections and there interfitting into the fianges of the stator units, all dust and dirt will be shielded from the parts and such casing will also act as an electrostatic shield thereby preventing stray currents from emanating therefrom which consequently will avoid the distortion of signals. It will `also be readily understood that while a vernier is unnecessary by reason of the distribution of the wave lengths over practically the entire dial that if the pitch of the groove in the shafts is varied, a multiple or micrometer dial can be used.

While I have shown and described a preferred embodiment of my invention, it will be readily understood by those skilled in the art that the same is capable of modification, variation and introduction of mechanical equivalents without departing from the spirit of the invention or sacrificing any of its advantages. These are therefore contemplated in so far as they may fall within the scope of the appended claims.

I claim:

l. A condenser comprising a stator and a' slider each composed of integrally formed concentric plates, a shaft for operating said slider, and means for adjusting the capacity of said condenser independent of said shaft,

said means comprising a guide member operated by an eccentric member for imparting a slight rotation to said slider.`

2. In a multiple-unit condenser, each unit comprising a stator and a slider each having a series of concentric plates, a shaft for operating the slider of one unit, a hollow shaft for operating the other units, said shafts having' spiral grooves thereon, means onsaid sliders engaging said grooves for changing the capacity relation between the plates of the stators and sliders, and means for independently adjusting the capacity .of each unit to synchronize the whole.

l 3. In a multiple-unit condenser, each unit comprising a stator and a slider, flanges on said stators having circumferential grooves therein, casing sections having their` edges resting in sai grooves, and means for uniting the said'stators in order to maintain said casing sections and thus shield said condenser units.

4i. 'A condenser comprising a stator ami a slider each composedvot concentric plates, a v shaft for operating said slider, guide means on said slider operating in a guideway 'for directing said slider axially, an spring means for urging and maintaining said guide means against one side of said guideway for preserving the proper relation of said slider with said stator,

in witness whereof, i have hereunto suhscribed my name.

REUBEN B. BENJAMIN.

mossos 

